Narrow complex tachycardias Flashcards
Give the ECG features of atrial fibrillation
irregularly irregular NO P waves lack of an isoelectric baseline variable ventricular rate QRS <120
what does the QRS complex represent
ventricular depolarisation
what is a normal QRS value, and when is it considered prolonged
between 0.08s and 0.10s
prolonged = >0.12s
give the causes of atrial fibrillation
Alcohol and caffeine, acid-base disturbance
Thyrotoxicosis
Rheumatic fever and mitral valve pathologies
IHD
Atrial myxoma
Lungs (pulmonary HTN, PE, pneumonia)
Pharmacological
Iatrogenic
Blood pressure
what are the three most common causes of atrial fibrillation
IHD
HTN
Mitral valve pathologies
describe the general rule of thumb for management of AF
asymptomatic or mild symptomatic patients = RATE control
Symptomatic patients, age >65 or concominant HF = RHYTHM control
how do you assess the need for anticoagulation in AF
CHADs VASC score -
how do you RATE control in AF
monotherapy with either a beta-blocker or a calcium channel blocker
second line: combination therapy with Digoxin + CCB or BB
how do you RHYTHM control in chronic AF
give a beta blocker
+ if ventricular impairment, amiodarone
or
if no ventricular impairment, dronedarone
how do you RHYTHM control in chronic paroxysmal AD
flecanide
how do you RHYTHM control in acute AF
if symptomatic for <48hr IMMEDIATE CARDIOVERSION
if no structural HD use IV flecanide or amiodarone
if structural HD use amiodarone
If symptomatic for >48h do DELAYED CARDIOVERSION
with TTE guided cardiovesion
what is atrial flutter
a supraventricular tachycardia caused by a re-entry circuit within the right atrium
how does atrial flutter normally present
breathlessness and palpitations
syncope and severe dyspnoea
what is the commonest cause of palpitations in patients with no structural heart anomalies
atrioventricular nodal re-entrant tachycardia
what with the ECG show in AVNRT
tachycardia of 140-280 bpm with normal and regular QRS complexes. There will be either
No visible P-waves (hidden within the QRS complex) or P-waves immediately before the QRS or P-waves immediately after the QRS complex